Shedding Light on Lumen Depreciation: Metal Halide vs. LED

In the world of high intensity lighting technology, two popular choices stand out: the legacy technology of metal halide and the modern technology of LED. For decades metal halide was promoted as the most advanced and best option, however as lighting technology evolved, LEDs have taken the throne.

There are many factors that set these two options apart, but one of the most convincing is lumen depreciation. In this blog we’ll dive into the differences between metal halide and LED in terms of lumen depreciation to discuss how the rapid light loss of metal halide makes retrofitting to LED a no-brainer option.

Metal halide lamps have been a staple in commercial and industrial lighting for many years. These lamps produce bright light by passing an electric current through a mixture of gases and halides inside an arc tube. However, one downside of metal halide lamps is their tendency to experience lumen depreciation over time and almost immediately. This means that the brightness of the light they emit decreases as they age, leading to a somewhat rapid decline in illumination levels.

When comparing the two technologies we could discuss factors such as product life ratings, fixture size, energy efficiency and others, but what most people consider when retrofitting is the quality and brightness of the light source.

LED (Light Emitting Diode) technology has revolutionized the lighting industry with its energy efficiency and longevity. LEDs are known for their minimal lumen depreciation compared to traditional lighting sources like metal halide. LED lights can maintain a high level of brightness throughout their lifespan, which can be significantly longer than that of metal halide lamps. This means that you can enjoy consistent illumination without worrying about a noticeable decrease in light output over time.

Proponents of traditional metal halide lamps often talk about their high “initial lumens” which, for example, on a 400W metal halide is approximately 36,000 lumens. However, metal halide lamps tend to lose their lumens very quickly. It’s not uncommon to see metal halide lamps begin to lose their lumens within weeks and could lose 20% of their light output in the first 6 months of operation. Within 10,000 hours of operation a metal halide lamp will often be operating at half the light output of what it was installed. Another thing to consider is that metal halide lamps are omni-directional so when used within a fixture output is reduced by up to 30% depending on the reflectors used in the fixture.

Directional LED fixtures, on the other hand, lose very little light output in their first 10,000 hours. In fact, they maintain 70% of their initial lumens between 50,000 and 100,000 hours. They also are optically superior and able to control the directionality of the light. This helps maintain usable light because it eliminates light wasted in inefficient luminaires.

The difference in lumen depreciation between metal halide and LED can have practical implications for various applications. For example, in settings where consistent lighting levels are crucial, such as sports arenas, warehouses, or outdoor spaces, LED lighting may be the preferred choice due to its ability to maintain brightness levels over an extended period. On the other hand, metal halide lamps may still be suitable for applications where lumen depreciation is less of a concern or where the initial cost of installation is a significant factor.

So, when considering lumen depreciation, LED lighting emerges as a clear winner over metal halide. Its superior performance in maintaining brightness levels over time makes it a compelling choice for those looking for long-lasting, energy-efficient lighting solutions. By understanding the differences between these two technologies, you can make an informed decision that aligns with your specific lighting needs and preferences.

Frank Grobmeier has over 30 years of product management and marketing experience with lighting manufacturers including decades in general lighting and specialty lighting with traditional and LED sources. He currently serves as on the Fanlight / Naturaled marketing management team and resides in the Chicago area.